Soul-Stealer
These swords, of which there are only about half a dozen were created for the great warlords of the far west. Who were at constant war with the barbarian hordes. The swords gave their wielders a better chance at surviving a confrontation with barbarians.
The sword functions no differently than a magical sword of its bonus. However, if an opponent with 2 or greater HD or levels is killed with the sword, the sword transfers to the wielder some of the soul of the fallen. It does this by healing the wielder. If the wielder of the sword has a disease, blindness, nausea or any other ailment, the sword will attempt to cure it as a 3rd level cleric. If the wielder suffers only physical wounds, the sword will heal the wielder 1D4 for every HD or level past first of the victim. If the wielder is at full health with no diseases, sicknesses, curses or other ailments, instead of healing the sword will raise the character’s max hit points by 1 permanently.
Furthermore, any being killed by a Soul-Stealer is not easily resurrected, raised, or reincarnated, as a portion of their soul has been absorbed by another being. A creature/player killed by a Soul-Stealer can be brought back to life normally if the wielder of the sword who had stolen his/her/its life force has been slain. Otherwise, the deceased must be brought back by a priest of at least 20th level and the wielder must either be present and willing to make a personal sacrifice (permanently losing 1D4 hit points) or fail 3 consecutive saves vs. death. If the wielder fails the saves, the being is brought back and the wielder suffers a loss of 2D3 hit points permanently and is shocked for 1D8 hours from some of it’s life-force being wretched away. If the saves are successful nothing happens to the wielder, however they do feel an attempt was made to harm them badly, and the resurrection fails and cannot be attempted again for 2 days. Each repeated attempt to revive a victim of a Soul-Stealer gives the wielder a +1 on his/her saves vs. the effect. The Soul-Stealers simply work as normal magical weapons of the appropriate bonuses against undead.